The present invention relates to a fuel tank for a motor vehicle, and more particularly to a device for venting the fuel tank upon filling it with fuel.
Japanese Patent Application Laid Open 61-291218 discloses a fuel tank having a vent tube communicated with the atmosphere through a carbon canister, so that fuel supply to the fuel tank may be readily provided because of venting the tank.
FIG. 4 shows an improvement of such a fuel tank. A fuel tank 4 has a float valve 3, a first vent tube 1 connecting the float valve 3 with a carbon canister 10, and a second vent tube la connecting an upper portion of a filler pipe 6 with the first vent tube 1 through a solenoid operated valve 2 which is opened when fueling. The float valve 3 is arranged such that a float rises with the fuel to close an opening of the valve at a maximum level, thereby to close the vent tube to stop discharging the fuel from a filler nozzel 5, namely to stop the fuel supply.
In such a device, it may happen that the float does not fall because of sticking of the float, if the level of the fuel lowers, which disables the fuel supply. In addition, when the motor vehicle overturns and the vent tube 1 is cut off upstream of the solenoid-operated valve 2, a dangerous accident that the fuel flows out of the tank through the float valve may occur.